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Zhang, Jasmine

University of British Columbia

T2K (Tokai to Kamioka) is a long-baseline neutrino experiment designed to investigate neutrino oscillations. The neutrino beam is generated by colliding a proton beam with a graphite target. In order to characterize neutrino production and ensure target protection, the Optical Transition Radiation (OTR) monitor measures the profile and position of the proton beam. However, we observe a discrepancy between the beam width measured by the upstream beam monitors and OTR which could be caused by a broad background present in OTR images. We hypothesize this background light originates from scintillation induced by the proton beam. We build a Geant4 simulation to model primary scintillation from direct excitation of the helium gas by the proton beam as well as secondary scintillation originating from particles produced in interactions between the proton beam and its surrounding geometry. By comparing the spatial distribution of the background light to the OTR signal from our simulation study we develop an accurate background light model essential for improving OTR measurements. Minimizing uncertainty in OTR light production mechanisms is critical for fine-tuning the proton beam orbit at the onset of the T2K experiment while also providing significant insights for physics analysis.

Text

2025-01-06

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/90063

Physics

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/